Wafer inspection method and wafer probing system

ABSTRACT

A wafer inspection method was provided. A motorized chuck stage is controlled by a control rod to be displaced between an upper position and a lower position of an adjustment range along a Z-axis direction, to change a relative position of a wafer on the motorized chuck stage relative to a probe. The control rod is movable between an upper limit position and a lower limit position in a displacement range. The wafer inspection method includes: determining a position of the control rod in the displacement range based on a measurement signal; determining a moving direction and a moving distance of the control rod based on a change of the measurement signal; generating a control signal based on the moving distance of the control rod; and controlling, based on the control signal, the motorized chuck stage and a camera stage to be displaced the same distance.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 62/599,051, filed onDec. 15, 2017, the entire contents of which are hereby incorporated byreference.

BACKGROUND Technical Field

Embodiments of the present invention relate to a semiconductorinspection method.

Related Art

With the development of a semiconductor technology, application ofintegrated circuits is more popular. In a process of making theintegrated circuits or after the process is completed, to screen out adefective product, a test signal needs to be transmitted, by using atest apparatus, to an integrated circuit to test whether the integratedcircuit meets expectations, to control and manage a delivery yield ofthe integrated circuits. Herein, in a current test technology, a probeof a probe apparatus may come into direct contact with a pad or aninput/output pad (I/O pad) on a to-be-tested circuit (for example, awafer), the test apparatus sends the test signal to the to-be-testedcircuit through the probe for testing, and a test result is returned tothe test apparatus through the probe for analysis.

In the currently known test apparatus, when the probe comes into contactwith the to-be-tested circuit for inspection, a motorized chuck stage isequipped with the wafer. And the motorized chuck stage can rotate andmove along a X-direction, a Y-direction, and a Z-direction. The probe isfixed on the center of a probe platen which is movable along with alongitudinal direction. And the probe platen is disposed above themotorized chuck stage. To execute probing, the motorized chuck stage anda camera keep focusing on the wafer. The probe comes into contact withthe pad from top to bottom relative to the to-be-tested circuit on thewafer to complete inspection.

The probe platen also needs to be equipped with other instrumentsrequired for testing. During probe testing, the height of the probeoften needs to be finely adjusted, and the probe is slightly movedupwards to observe whether a probe trace generated by the probe meetsexpectations or determine whether the probe really comes into contactwith the pad, in both mechanical and control aspects, it is ratherdifficult to drive the probe platen bearing a heavy weight to beprecisely finely adjusted. Therefore, to prevent from damage of theimproper sustainable force between the wafer and the probe, using thecamera to confirm the location of the probe and then start probing. Toprevent from the damage of the probe and the wafer, it's necessary tocontrol the displacement between the probe and the wafer.

SUMMARY

The present invention provides a wafer inspection method. A motorizedchuck stage is controlled by a control rod to be displaced between anupper position and a lower position of an adjustment range along aZ-axis direction, to change a relative position of a wafer on themotorized chuck stage relative to a probe. The control rod is movablebetween an upper limit position and a lower limit position in adisplacement range. The wafer inspection method includes: determining aposition of the control rod in the displacement range based on ameasurement signal; determining a moving direction and a moving distanceof the control rod based on a change of the measurement signal;generating a control signal based on the moving distance of the controlrod; and controlling, based on the control signal, the motorized chuckstage and the camera stage to be displaced the same distance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a step flowchart of an embodiment of a wafer inspection methodaccording to the present invention;

FIG. 2 is a schematic diagram of a wafer probing system for implementinga wafer inspection method;

FIG. 3 is a partial schematic diagram of an embodiment of a waferprobing system;

FIG. 4 is another schematic diagram of a wafer probing system forimplementing a wafer inspection method;

FIG. 5 shows an embodiment of a relative relationship between a changeof a measurement signal and a displacement distance of a motorized chuckstage in a wafer inspection method according to the present invention;

FIG. 6 shows another embodiment of a relative relationship between achange of a measurement signal and a displacement distance of amotorized chuck stage in a wafer inspection method according to thepresent invention;

FIG. 7 shows still another embodiment of a relative relationship betweena change of a measurement signal and a displacement distance of amotorized chuck stage in a wafer inspection method according to thepresent invention; and

FIG. 8 shows yet another embodiment of a relative relationship between achange of a measurement signal and a displacement distance of amotorized chuck stage in a wafer inspection method according to thepresent invention.

DETAILED DESCRIPTION

Referring to FIG. 1 with reference to FIG. 2, FIG. 3, and FIG. 4, FIG. 1is a step flowchart of an embodiment of a wafer inspection methodaccording to the present invention, and FIG. 2 and FIG. 4 are schematicdiagrams of a wafer probing system for implementing a wafer inspectionmethod. FIG. 3 is a partial schematic diagram of an embodiment of awafer probing system.

A wafer probing system 100 shown in FIG. 2 and FIG. 4 is configured toinspect an electrical condition of a wafer W. In an embodiment, thewafer probing system 100 includes a case 10, a control rod 20, amotorized chuck stage 30, a probe platen 40, a probe 50, a displayscreen 60, a camera stage 70, a controller 80 and a sensor.

The motorized chuck stage 30 may be disposed to be displaced in the case10 along a path in a Z-axis direction. The motorized chuck stage 30 isadapted to support the wafer W. The probe platen 40 is fixed on the case10. The probe 50 is disposed above the motorized chuck stage 30.Specifically, the probe platen 40 is disposed above the motorized chuckstage 30, and the probe 50 is disposed on the probe platen 40.The camerastage 70 is configured to take a picture of the motorized chuck stage30. Specifically, the camera stage 70 is disposed on the case and facestowards the wafer W to take a picture of the wafer W on the motorizedchuck stage 30 when probe testing is performed on the wafer W, toobserve a probe testing state. The controller 80 is communicativelycoupled to the motorized chuck stage 30 and the camera stage 70. Thecontrol rod 20 can be displaced between an upper limit position H1 and alower limit position H2, and the control rod 20 is electricallyconnected with the controller 80. The sensor is communicatively coupledto the control rod 20 and the controller 80, when the position of thecontrol rod 20 is changed, the sensor generates a control signal, andthe controller 80 is configured to control the motorized chuck stage 30and the camera stage 70 to move the same distance according to thecontrol signal along the Z-axis direction.

The display screen 60 is communicatively coupled to the camera stage 70.The display screen 60 includes a user interface, the user interface iscapable of showing a current position of the motorized chuck stage 30.

In an embodiment, the wafer probing system 100 further includes a firstdriving unit 91 and a second driving unit 92. The first driving unit 91is connected with the motorized chuck stage 30. The second driving unit92 is connected with the camera stage 70. The controller 80 iscommunicatively coupled to the first driving unit 91, the second drivingunit 92, and the control rod 20. The present invention is not limitedthereto.

Herein, two ends towards the Z-axis direction are an upper direction Z1and a lower direction Z2, and the probe platen 40 is located in theupper direction Z1 of the motorized chuck stage 30 relative to themotorized chuck stage 30. In addition, the motorized chuck stage 30 maybe displaced along the Z-axis direction to be close to or far away fromthe probe platen 40, the wafer W on the motorized chuck stage 30 comesinto contact with a tip of the probe 50, the tip of the probe 50 comesinto contact with the pad P of the wafer W and pierces an oxide layer toform an electrical connection for inspection. Herein, the motorizedchuck stage 30 may feed along the Z-axis direction in two stages, and afeed amount along the Z-axis direction in a first stage is greater thana feed amount along the Z-axis direction in a second stage.

Specifically, the wafer probing system 100 may set a displacement amountof the motorized chuck stage 30 along the Z-axis direction in the firststage by using the touch display screen 60. After displacement in thefirst stage, the motorized chuck stage 30 may be set at a height atwhich the wafer W comes into contact with the probe 50 and can performinspection. Herein, this may be referred to as set of an inspectionheight. Displacement of the motorized chuck stage 30 along the Z-axisdirection in the second stage is a fine adjustment distance required forobserving, after the height at which the wafer W comes into contact withthe probe 50 and performs inspection is set, whether a probe trace ofthe probe 50 or the tip of the probe 50 is really aligned with the pad Pof the wafer W.

Further, in an embodiment, the motorized chuck stage 30 is controlled bythe control rod 20 to be displaced along the Z-axis direction, and thecontrol rod 20 may control the motorized chuck stage 30 to be displacedbetween an upper position D1 and a lower position D2, and a spacebetween the upper position D1 and the lower position D2 is an adjustmentrange D. Herein, a distance of the adjustment range D needs to begreater than an over drive (OD) of the probe 50 piercing the oxidelayer, and when the adjustment range D is greater than the OD, it can beensured that the displacement of the motorized chuck stage 30 can makethe wafer W really get away from the tip of the probe 50.

When the motorized chuck stage 30 changes a position in the adjustmentrange D, a relative position of the wafer W on the motorized chuck stage30 relative to the probe 50 can be simultaneously changed. In this way,the tip of the probe 50 gets away from the wafer W to observe the probetrace generated on the pad P in a test process or adjust a position ofthe tip of the probe 50.

Herein, the control rod 20 is limited to moving in a displacement rangeH, and the displacement range H extends a length along the Z-axisdirection. Therefore, the displacement range H includes an upper limitposition H1 and a lower limit position H2 in the Z-axis direction, andthe control rod 20 can be displaced between the upper limit position H1and the lower limit position H2. That is, the displacement range H isdefined by a space between the upper limit position H1 and the lowerlimit position H2. The control rod 20 may be disposed to be displaced ina sliding groove 21 extending along the Z-axis direction, two ends ofthe sliding groove 21 are the upper limit position H1 and the lowerlimit position H2, and a length of the sliding groove 21 in the Z-axisdirection is the displacement range H. Further, in this embodiment,displacement of the control rod 20 between the upper limit position H1and the lower limit position H2 can correspondingly control displacementof the motorized chuck stage 30 between the upper position D1 and thelower position D2.

In an embodiment, referring to FIG. 1, FIG. 1 is a step flowchart ofusing a wafer probing system 100 to perform a wafer inspection method.When inspection is started, first, a position of the control rod 20 isdetermined based on a measurement signal (step S11). After the positionof the control rod 20 is determined, a displacement amount of themotorized chuck stage 30 subsequently controlled to be displaced isdefined based on a moving distance of the control rod 20 subsequentlyoperated to move.

Herein, a source of the measurement signal based on which the positionof the control rod 20 is determined may be an analog signal or a digitalsignal. In an embodiment, in a manner of determining the position of thecontrol rod 20 by using the digital signal, a plurality of sensors maybe disposed in the displacement range H in which the control rod 20moves, each sensor is respectively communicatively coupled to thecontrol rod 20 and the controller 80, and each sensor may generate aprobing signal corresponding to the position of the control rod 20. Thecontroller 80 is configured to generate a control signal according tothe probing signal, the first driving unit 91 and the second drivingunit 92 are adapted to control the motorized chuck stage 30 and thecamera stage 70 move according the control signal.

For example, when the displacement range H of the control rod 20 is tencentimeters, the sensors may be disposed at positions at intervals ofone centimeter in the displacement range H, and each sensor iscorrespondingly located at different positions of the control rod 20 inthe displacement range H. When the control rod 20 is located at thedifferent positions in the displacement range H, the sensor at theposition where the control rod 20 is located generates a digitalmeasurement signal, and the position of the control rod 20 in thedisplacement range H can be determined by using the digital measurementsignal. Certainly, when the control rod 20 is displaced, a displacementdistance of the control rod 20 may be determined by using a change ofthe digital measurement signal. The interval between the foregoingsensors and the quantity of the sensors are only examples for ease ofdescription. The present invention is not limited thereto, and may beadjusted based on different using habits or requirements. In anembodiment, the sensor may be a proximity switch.

In an embodiment, in a manner of determining the position of the controlrod 20 by using an analog measurement signal, the control rod 20 may beconnected to an electronic element that may generate the analog signalcorresponding to displacement of the control rod 20. Specifically, thecontrol rod 20 may be connected to an electronic element that maygenerate a voltage change, a resistance change, a capacitance change, oran inductance change. When the control rod 20 is located at eachposition of the displacement range H, a corresponding analog measurementsignal value may be measured. In a specific embodiment, when the controlrod 20 is connected to the electronic element that may generate thevoltage change, the control rod 20 may obtain corresponding differentvoltage values at the positions in the displacement range H throughmeasurement. In this way, detecting the voltage value can determine theposition of the control rod 20 in the displacement range H. Certainly,when the control rod 20 is displaced, the moving distance of the controlrod 20 may also be learned corresponding to a change of the voltagevalue. Herein, a general computer system can read only the digitalsignal. Therefore, in this embodiment, a measured analog signal mayfurther be converted into a digital signal for the computer system toread and determine the analog signal.

Then, further, when the control rod 20 is operated to move, a movingdirection and a moving distance of the control rod 20 is determinedbased on a change of the measurement signal (step S12). In anembodiment, when the position of the control rod 20 is determined to belocated at the lower limit position H2 of the displacement range H,herein a moving distance of the control rod 20 moving towards the upperlimit position H1 may be determined.

After the moving distance of the control rod 20 displaced from the lowerlimit position H2 to the upper limit position H1 is determined based onthe change of the measurement signal, a control signal is generatedbased on the moving distance of the control rod 20 (step S13). Then, themotorized chuck stage 30 and the camera stage 70 are controlled, basedon the control signal, to be displaced the same distance (step S14). Inthis embodiment, the controller 80 is configured to generate the controlsignal, the first driving unit 91 and the second driving unit 92 arerespectively adapted to control the motorized chuck stage 30 and thecamera stage 70 to move the same distance according to the controlsignal. Herein, a distance between the motorized chuck stage 30 and thecamera stage 70 is not change after move. In other embodiment, themotorized chuck stage 30 and the camera stage 70 may movesimultaneously. The present invention is not limited thereto.

In this embodiment, the control signal based on the moving distance ofthe control rod 20 displaced from the lower limit position H2 to theupper limit position H1 controls the motorized chuck stage 30 to bedisplaced from the upper position D1 to the lower position D2. That is,a displacement direction of the control rod 20 is opposite to adirection in which the motorized chuck stage 30 is controlled to bedisplaced.

More specifically, a relative relationship of correspondingly adjustingthe displacement amount of the motorized chuck stage 30 based on themoving distance of the control rod 20 may have differentcorrespondences, as shown in FIG. 5 to FIG. 8. Herein, the differentcorrespondences of correspondingly adjusting the displacement amount ofthe motorized chuck stage 30 based on the moving distance of the controlrod 20 may be software or a program that is written into hardware.

Referring to FIG. 5, in an embodiment, there is a linear correlationbetween a proportion of the moving distance of the control rod 20 in thedisplacement range H and a proportion of a displacement distance of themotorized chuck stage 30 in the adjustment range D. In a specificembodiment, as shown in FIG. 5, when the control rod 20 is displaced sothat the corresponding measurement signal changes, there may be a 1:1linear correlation between the displacement distance of the motorizedchuck stage 30 and the change of the measurement signal corresponding toan movement of the control rod 20. That is, when the operator adjuststhe control rod 20 to the lower limit position H2, it may be intuitivelyconsidered as the initial position of the motorized chuck stage 30, andadjusting the position of the control rod 20 in the displacement range Hmay directly correspond to a position ratio of the motorized chuck stage30 in the displacement range H, thereby facilitating observation andoperation of the operator. Certainly, the correspondence between thechange of the measurement signal corresponding to the movement of thecontrol rod 20 and the displacement distance of the motorized chuckstage is not limited to a 1:1 linear correlation, and may be changed to1:2, 2:1 or other proportions based on an environment or a hardwarerequirement.

In another embodiment, referring to FIG. 6 to FIG. 8, there mayalternatively be a nonlinear correlation between the change of themeasurement signal corresponding to the movement of the control rod 20and the displacement distance of the motorized chuck stage 30, as shownin FIG. 6 to FIG. 8. Specifically, the relative relationship between thechange of the measurement signal corresponding to the movement of thecontrol rod 20 and the displacement distance of the motorized chuckstage 30 is a curve. In this way, the displacement distance of themotorized chuck stage 30 and a change of the analog signal correspondingto the movement of the control rod 20 meet expectations. Herein, thecurve of the relative relationship between the change of the measurementsignal and the displacement distance of the motorized chuck stage 30 maybe adjusted based on a requirement.

In another embodiment, in addition to controlling the relationshipbetween the change of the measurement signal and the displacementdistance of the motorized chuck stage 30 by using software, adisplacement range (for example, a maximum displacement amount and aminimum displacement amount) of the motorized chuck stage 30 can befurther limited, thereby meeting different hardware requirements.

In an embodiment, a plurality of control nodes is included between theupper limit position H1 and the lower limit position H2 of thedisplacement range H, each control node generates a differentmeasurement signal value, and when a measurement signal value at theposition where the control rod 20 is located is the same as themeasurement signal value corresponding to the control node, the controlsignal can be generated. The foregoing control nodes may be physicalposition sensors (which output digital signals) or unphysical controlnodes (analog signal values) that define a position based on a movingdistance signal.

In an embodiment, the control nodes may be evenly disposed in thedisplacement range H. For example, the displacement range H has a rangeof ten centimeters, when the control nodes are evenly disposed in thedisplacement range H, measurement signal values at the positions at theintervals of one centimeter in the displacement range H conform to themeasurement signal values corresponding to the control nodes, and adistance (one centimeter) between control nodes is defined as a movingdistance segment. Herein, the displacement range H is divided into themoving distance segments corresponding to the quantity of the controlnodes. Therefore, when the moving distance of the control rod 20 isdetermined to conform to a multiple of the moving distance segment, thecontrol signal can be generated, and a proportion of the moving distancein the displacement range H is the same as the displacement distance ofthe motorized chuck stage 30 in the adjustment range D.

Herein, if the entire adjustment range D of the motorized chuck stage 30has a range of 100 μm, the motorized chuck stage 30 may becorrespondingly adjusted to be displaced for a distance of 10 μm byadjusting the control rod 20 to be displaced for a moving distancesegment. In this way, in addition to limiting the control rod 20 tocontrol displacement of the motorized chuck stage 30 each time based ona preset distance, it is defined in advance that adjustment of thecontrol rod 20 each time correspondingly controls the displacementdistance of the motorized chuck stage 30, and the operator may foreknowthe adjusted displacement distance of the motorized chuck stage 30 byusing times of adjusting the control rod 20, thereby improving operationconvenience.

In addition, distribution of the positions of the control nodescorresponding to the control rod 20 is not limited to even distributiondisclosed in the foregoing embodiments. In an embodiment, the controlnodes in the displacement range H are not evenly distributed, adistribution density of the control nodes in the range closer to thelower limit position H2 is greater than a distribution density of thecontrol nodes in the range closer to the upper limit position H1. Inthis way, when the position of the control rod 20 in the displacementrange H is closer to the lower limit position H2, it indicates that theposition of the motorized chuck stage 30 is closer to the probe 50. Inthis state, to prevent excessive feeding of the motorized chuck stage 30from damaging the probe 50, the control nodes closer to the lower limitposition H2 indicate a greater distribution density, and a distance ofthe control rod 20 to generate the control signal due to displacement isshorter. In addition to more finely controlling the displacementdistance of the control rod 20, the position of the motorized chuckstage 30 can be correspondingly more accurately adjusted accordingly,thereby avoiding damage of the probe 50.

It may be learned from the foregoing embodiments of differentdistribution of the control nodes in the displacement range H that thecontrol nodes may be adjusted to relatively change a displacementdistance of the motorized chuck stage 30 driven by the control rod 20moving each time, and the operator may adjust the control nodes due todifferent requirements or hardware limits.

Further, based on the foregoing descriptions, when more control nodesare required in the displacement range H, an architecture determiningthe position of the control rod 20 by using the analog signal is betterthan an architecture determining the position of the control rod 20 byusing the digital signal. Because sensors need to be increased,corresponding to the quantity of the control nodes, on the hardwarearchitecture determining the position of the control rod 20 by using thedigital signal, when the quantity of the control nodes increases, costsof the hardware architecture determining the position of the control rod20 by using the digital signal are higher. The hardware architecturedetermining the position of the control rod 20 by using the analogsignal does not have a same problem.

In addition, in an embodiment, the displacement distance of themotorized chuck stage 30 may be further continuously detected, asynchronization signal is generated based on the displacement distance,and the camera stage 70 is controlled, based on the synchronizationsignal, to be synchronously displaced. In this way, the position of themotorized chuck stage 30 and a position of the camera stage 70 aresynchronously changed, to ensure that the camera stage 70 can stillmaintain, after the motorized chuck stage 30 changes the position,focusing to obtain a clear image.

In this embodiment, continuous detection of the displacement distance ofthe motorized chuck stage 30 may be synchronously displayed on thedisplay screen 60, so that the operator can learn the position and anadjustment state of the motorized chuck stage 30 in real time, therebyimproving operation convenience, and accordingly reducing erroroperations.

In conclusion, the method in the foregoing embodiments, that is,determining the position of the control rod 20 based on the measurementsignal and finely adjusting, based on the moving distance of the controlrod 20, the motorized chuck stage 30 to be displaced, is not disclosedin the related art, and a person of ordinary skill in the art cannoteasily complete the foregoing embodiments of the present invention basedon the related art. In addition, a relative relationship between achange value of the measurement signal and the displacement amount ofthe motorized chuck stage 30, a displacement amount of the motorizedchuck stage 30 each time, or the maximum/minimum displacement amount ofthe motorized chuck stage 30 in the embodiments of the present inventionmay be changed based on a requirement or a hardware limit, therebyhaving optimal practicability.

Although the present invention has been described in considerable detailwith reference to certain preferred embodiments thereof, the disclosureis not for limiting the scope of the invention. Persons having ordinaryskill in the art may make various modifications and changes withoutdeparting from the scope and spirit of the invention. Therefore, thescope of the appended claims should not be limited to the description ofthe preferred embodiments described above.

What is claimed is:
 1. A wafer inspection method, wherein a motorizedchuck stage is controlled by a control rod to be displaced between anupper position and a lower position of an adjustment range along aZ-axis direction, to change a relative position of a wafer on themotorized chuck stage relative to a probe, and the control rod ismovable between an upper limit position and a lower limit position in adisplacement range, the wafer inspection method comprising: determininga position of the control rod in the displacement range based on ameasurement signal; determining a moving direction and a moving distanceof the control rod based on a change of the measurement signal;generating a control signal based on the moving distance of the controlrod; and controlling, based on the control signal, the motorized chuckstage and a camera stage to be displaced the same distance.
 2. The waferinspection method according to claim 1, wherein after the motorizedchuck stage is controlled, based on the control signal, to be displaced,there is a linear correlation between the change of the measurementsignal and a displacement distance of the motorized chuck stage.
 3. Thewafer inspection method according to claim 2, wherein after themotorized chuck stage is controlled, based on the control signal, to bedisplaced, a proportion of the displacement distance of the motorizedchuck stage in the adjustment range is equal to a proportion of themoving distance in the displacement range.
 4. The wafer inspectionmethod according to claim 1, wherein after the motorized chuck stage iscontrolled, based on the control signal, to be displaced, there is anonlinear correlation between the change of the measurement signal and adisplacement distance of the motorized chuck stage.
 5. The waferinspection method according to claim 1, wherein a plurality of controlnodes is comprised between the upper limit position and the lower limitposition of the displacement range, and when the measurement signal ofthe position of the control rod conforms to a measurement signalcorresponding to a control node, the control signal is generated basedon the moving distance.
 6. The wafer inspection method according toclaim 5, wherein the plurality of control nodes is evenly disposed inthe displacement range, the displacement range is divided into movingdistance segments corresponding to the quantity of the control nodes,the moving distance is a multiple of the moving distance segment, and aproportion of the moving distance in the displacement range is the sameas a proportion of a displacement distance of the motorized chuck stagein the adjustment range.
 7. The wafer inspection method according toclaim 5, wherein densities of the plurality of control nodes distributedin the displacement range are different.
 8. The wafer inspection methodaccording to claim 7, wherein a distribution density of the plurality ofcontrol nodes closer to the lower limit position is greater than adistribution density of the plurality of control nodes in the rangecloser to the upper limit position.
 9. A wafer probing system,comprising: a motorized chuck stage, adapted to support a wafer; aprobe, disposed above the motorized chuck stage; a camera stage,configured to take a picture of the motorized chuck stage; a controller,communicatively coupled to the motorized chuck stage and the camerastage; a control rod, capable of moving between an upper limit positionand a lower limit position, and the control rod electrically connectswith the controller; a sensor, communicatively coupled to the controlrod and the controller, when the position of the control rod is changed,the sensor generates a control signal, and the controller is configuredto control the motorized chuck stage and the camera stage to move thesame distance according to the control signal along a Z-axis direction;and a display screen, communicatively coupled to the camera stage, andthe display screen includes a user interface, the user interface iscapable of showing a current position status of the motorized chuckstage.